Electrical switch having adjustable conductive-liquid level

ABSTRACT

A device for protecting cars against skidding in curves, comprising a housing, filled with an electrically conducting liquid which is influenced by the centrifugal force when the car travels through the corner at speed, so that the level of the conducting liquid assumes an inclined position and the liquid can close or open an electrical circuit, leading to the switching-off of the ignition. By means of a displacer body the sensivity of the device can be adjusted.

limited States Patent van den Bosch [54] ELECTRICAL SWITCH HAVINGADJUSTABLE CUNDUCTKVE-LIQUHD LEVEL [72] Inventor: Mathiis van den Bosch,Rue des Ecoles, 72-Thorigne sur Due, France [22] Filed: Feb. 25, 1971[21] App1.No.: 118,900

[52] 11.8. C1 ..200/6L47, 200/190 [51] Int. Cl ..l-l01h 35/18 [58] Field01 Search.200/61.46, 61. 47, 152 R, 61.45; 280/112 A; 317/5; 303/7;335/51, 52

[56] References Cited UNITED STATES PATENTS 977,523 12/1910 Gustafson..200/152 1,623,326 4/1927 Whalen ....200/l52.8 X 1,806,236 5/1931Charles ..200/61.47 2,133,773 10/1938 Rossman et a1 ..267/11 Aug. 8,1972 2,147,506 2/1939 Stoner ..335/51 2,275,554 3/1942 Pollard ..335/523,184,566 5/1965 Kleinpeter ..200/l52.4 X 3,431,556 3/1969 Johnson..200/61.45 X 3,398,991 8/1968 Compton ..200/61.45 X 3,406,775 10/ 1 968Magnuski ..317/5 3,564,531 2/1971 Burgin ..200/61.47 X

Primary Examiner-Robert K. Schaefer Assistant ExaminerM. GinsburgAttorneyBreitenfeld & Levine [57] ABSTRACT A device for protecting carsagainst skidding in curves, comprising a housing, filled with anelectrically conducting liquid which is influenced by the centrifugalforce when the car travels through the corner at speed, so that thelevel of the conducting liquid assumes an inclined position and theliquid can close or open an electrical circuit, leading to theswitching-off of the ignition. By means of a displacer body thesensivity of the device can be adjusted.

4 Claims, 7 Drawing Figures P'ATENTEDAus 8 I972 SHEET 1 OF 2 PRIOR ARTINVENTOR: MATH/Is vmv DEN Beau BY g E ATTORNEYS ELECTRICAL SWITCH HAVINGADJUSTABLE CONDUCTIVE-LIQUID LEVEL This invention relates to a non-skiddevice provided with a housing, wherein there is a movable conductingliquid, cooperating with contacts disposed at a distance on either sideof the central plane through the housing.

Such a device is. known 'from US. Pat. No. 2, 1 33,773. In order toimprove theefiect this device is provided with damping partitions,mainly directed transversely to the direction of movement of the liquidconductor. The drawback of the known device is its suitability for aparticular type of vehicle only, so that it must be adjusted beforehandduring manufacturing. In operation the device is furthermore notadjustable so that no adaptation is possible, to various types of roadsurface or change of properties thereof owing to weather conditions, e.g., rain or snow, etc.

My invention avoids the aforementioned drawbacks by providing that thelevel of the liquid conductor can be adjusted by means of a displacerbody.

According to my invention the displacer body is preferably a rotatableeccentric part the level of the liquid separating layer then beingcontinuously adjustable without change of the total volume. The devicecan be very simply operated from the dashboard, e.g., by means of ahorizontal shaft protruding therethrough.

The device can be further improved and simplified, when between thecontacts there is mounted atleast one movable magnetizable body on whichacts an adjustable magnetic flux in order to influence the movement ofthe liquid conductor in a simple and exactly controllable way.

In the housing no passage openings for the operating mechanisms need beprovided, as in a mechanical device; furthermore the control can beefiected at a distance in a simple way, e.g., by adjustingbymeans of avariable resistor the current which generates the electromagnetic field,while the device itself may be placed practically everywhere,preferablyin thevicinity of the ignition coil in order to keep theconnections as short as possible. The rheostat, of modest dimensions,used for adjusting the current in the magnet coil is placed within easyreach on the dashboard.

The adjustibility may be made more or less auto matic by feeding thecoil by a pulsating direct current which is a function of the roadspeed.

At a high speed, that is to say in case at higherinterruptionfrequencies, the apparent coil resistance increases, so that at aconstant battery voltage the magnetizing current decreases and therewiththe magnetic field restraining the movement of .the immersion body. Thesensitivity increases with an increase of the speed in accordance withthe increasing skid danger.

Lurching of the liquid conductor may be further counteracted by coveringsame with a liquid insulator; the two mediums should not be mixable.

The liquid layer floating on the surface of the conductive layer has adamping effect thereon. Moreover practically no sparks are producedduring switching which is of great importance after an accident in viewof the risk of fire.

Preferably mercury is used as a liquid conductor and glycerol ortransformer oil as an insulating liquid.

The device may also serve to switch on the current instead ofinterrupting the current as according to the aforementioned arrangement,which can be simply achieved by providing the contacts not below, butabove the level of the liquid conductor to which the current is thensupplied, e. g., via the displacer body.

In the drawings:

FIG. 1 is a front view of a device according to the prior art;

FIG. 2 is a front view of a device provided with a displacer body andlower contacts;

FIG. 3 and 4 are front views of a device with an eccentric displacerbody in two positions;

FIG. 5 is diagram of an electrically adjustable device;

FIG. 6 and 7 are diagrams of connections to be used with theconstruction according to FIG. 5.

On the hollow and for the greater part spheric body 1 is placed a cover2 (e.g. clamped in the opening in the top part) provided with twoelectric contacts 3 reaching into the liquid conductor 4. The device ismounted in series with an electric lead, e.g., of the ignition device ina vehicle.

On rounding a curve the liquid conductor will assume an inclinedposition, see dash line 4'in dependence of the speed-and radius,whereby, in case of a relatively too high speed, the contact is brokenand the ignition cut ofl. On returning to normal the connection isautomatically re-established. Since the contacts 3 are perpendicular tothe longitudinal direction of the vehicle the effect is not influencedby an inclined position.

Obviously the housing need not be spheric, but may also be shapeddifferently. Although the housing is preferably made of plastic, metalscan also be used, provided both the contacts 3 and the device itself areinsulated.

A further improvement is obtained by providing on top of the liquidconductor 4 a non conductive layer 5 of liquid (e.g., glycerolortransforrner oil) (see FIG. 2), whereby oscillations, for instancebrought about by an extremely uneven road surface are damped and a verydependable operation of the device ensured.

By turning the screw-shaped displacer body 6 protruding through thecover 2 in or out the level of the liquid layer 4 over the contacts 3can be raised or lowered, while the head of the screw-shaped body 6 maybe provided with marks to fix in a simple way the position thereof andas a consequence as well the height of the level of the liquid conductor4 whereby the device thus being rapidly and exactly adaptable to anykind of motor car, to the properties and condition of the tires and evenin operation, to the load of the vehicle and the condition of the roadsurface.

In an eflicient embodiment as shown in FIG. 3 the contacts 3' arelikewise disposed in the lower part of the house 1. Obviously alsoanother adequate construction can be applied. The eccentric body 7 canbe turned externally by means of a shaft 8. The effect is clear from thefigure, which also shows that the total volume remains constant in anyposition. The contacts 3 may also be provided above the level of the.liquid conductor 4; if current is supplied thereto, e.g., via ascrew-shaped displacer body according to FIG. 2, then on rounding acurve at a specific speed and radius, the circuit will not be broken butclosed, whereby, e.g., a warning signal or the like can be activated.

With the electric control mechanism shown in FIG. 5 the housing 1 (e.g.,a closed glass container) with contacts 3 and a liquid conductor-4 isprovided with a magnetizable body and separate conductive windings 9which can be connected with a current source. On passage of a currentthe generated magnetic field will influence the movement of themagnetizable body 10 and consequently the flow of the liquid conductor.By changing the current intensity, the operative characteristic of thedevice can thus be influenced.

In the circuit diagram of FIG. 6 the normal ignition switch is denotedby 11, an adjustable resistor for adjusting the intensity of currentthrough the windings by 9, ignition coil and the current distributor by13, 14, respectively, the chassis serving as return path.

According to the circuit diagram of FIG. 7 the variable resistor 12 isconnected to earth via the contact breaker points 14, adding a capacitor15 across the coil 9, through which now passes a pulsating directcurrent in conformity to the frequency of the interruptor 14, to wit ofthe motor and therefore indirectly of the driving speed. Since theapparent resistance of the coil will increase with increasing frequencyof the current and therefore, when the voltage is constant, themagnetizing current decreases, the magnetizable body is less influencedand as a consequence the effect is more sensitive, because of thedecrease of the braking effect on the liquid conductor. The device thuswill react more rapidly at a higher speed in conformity with the thenincreased danger of skidding.

Construction, mounting, adjustment as well as the adjustment duringoperation are surprisingly simple.

Having thus described my invention, what is claimed as new and desiredto be secured by Letters Patent is:

1. An electrical switch comprising a housing, a movable liquid conductorwithin said housing, a pair of spaced-apart electrical contacts withinsaid housing for making direct contact with said liquid conductor, saidcontacts beinglocatedon opposite sides of a vertical median planeextending through said housing, and a displacer body within said housingand movable into different positions wherein it can directly contact anddisplace dilferent amounts of said liquid conductor so as to adjust thelevel of said liquid conductor, said displacer body being a membereccentrically mounted for rotation with respect to said housing about anaxis parallel to the surface of said liquid conductor.

2. An electrical switch as defined in claim 1 including a liquidinsulator within said housing, said liquid insulator being immisciblewith said liquid conductor.

3. An electrical switch as defined in claim 2 wherein said liquidconductor is mercury, and said liquid insulator is selected from thegroup consisting of glycerol and transformer oil.

4. An electrical switch comprising a housing, a movable liquid conductorwithin said housing, a pair of spaced-apart electrical contacts withinsaid housing for making direct contact with said liquid conductor, saidcontacts being located on opposite sides of a vertical median planeextending through said housing, a magnetizable member movable freelywith said liquid conductor within said housing, means for producing amag netic flux which acts on said member to resist free movement of saidmember and said liquid conductor, and means for adjusting the magnitudeof said flux whereby said member controls the resistance to movement ofsaid conductor.

1. An electrical switch comprising a housing, a movable liquid conductorwithin said housing, a pair of spaced-apart electrical contacts withinsaid housing for making direct contact with said liquid conductor, saidcontacts being located on opposite sides of a vertical median planeextending through said housing, and a displacer body within said housingand movable into different positions wherein it can directly contact anddisplace different amounts of said liquid conductor so as to adjust thelevel of said liquid conductor, said displacer body being a membereccentrically mounted for rotation with respect to said housing about anaxis parallel to the surface of said liquid conductor.
 2. An electricalswitch as defined in claim 1 including a liquid insulator within saidhousing, said liquid insulator being immiscible with said liquidconductor.
 3. An electrical switch as defined in claim 2 wherein saidliquid conductor is mercury, and said liquid insulator is selected fromthe group consisting of glycerol and transformer oil.
 4. An electricalswitch comprising a housing, a movable liquid conductor within saidhousing, a pair of spaced-apart electrical contacts within said housingfor making direct contact with said liquid conductor, said contactsbeing located on opposite sides of a vertical median plane extendingthrough said housing, a magnetizable member movable freely with saidliquid conductor within said housing, means for producing a magneticflux which acts on said member to resist free movement of said memberand said liquid conductor, and means for adjusting the magnitude of saidflux whereby said member controls the resistance to movement of saidconductor.